Open Access. Powered by Scholars. Published by Universities.®

Ecology and Evolutionary Biology Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 10 of 10

Full-Text Articles in Ecology and Evolutionary Biology

Diet Composition And Mercury Exposure In Bank Swallows (Riparia Riparia) Breeding At Lakeshore And Aggregate Pits, Corrine S. V. Génier Dec 2019

Diet Composition And Mercury Exposure In Bank Swallows (Riparia Riparia) Breeding At Lakeshore And Aggregate Pits, Corrine S. V. Génier

Electronic Thesis and Dissertation Repository

Bank Swallows (Riparia riparia), a threatened species in Ontario, breed primarily in banks at lakeshores and in artificial aggregate pits. Inland pits may be ecological traps for this species, but the relative tradeoffs between these two nesting habitats are unknown. Availability of aquatic emergent insects at lakeshores may have associated nutritional benefits (e.g. Omega-3 fatty acids) and contaminants (e.g. mercury) that can directly influence juvenile growth. This study compares these breeding habitats to evaluate dietary differences as revealed by fatty acids, stable isotopes (δ13C, δ15N, δ2H), fecal DNA barcoding, and mercury. Lakeshore-nesting …


The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev Sep 2019

The Stability Of Temperate Lakes Under The Changing Climate, Aleksey Paltsev

Electronic Thesis and Dissertation Repository

There is a collective prediction among ecologists that climate change will enhance phytoplankton biomass in temperate lakes. Yet there is noteworthy variation in the structure and regulating functions of lakes to make this statement challengeable and, perhaps, inaccurate. To generate a common understanding on the trophic transition of lakes, I examined the interactive effects of climate change and landscape properties on phytoplankton biomass in 12,644 lakes located in relatively intact forested landscapes. Chlorophyll-a (Chl-a) concentration was used as a proxy for phytoplankton biomass. Chl-a concentration was obtained via analyzing Landsat satellite imagery data over a 28-year period (1984-2011) and using …


Above- And Belowground Community Linkages In Boreal Peatlands And Climate Warming Implications, Caitlyn Lyons Sep 2019

Above- And Belowground Community Linkages In Boreal Peatlands And Climate Warming Implications, Caitlyn Lyons

Electronic Thesis and Dissertation Repository

Aboveground plants provide resources to the belowground microbial community via plant litter and, in turn, the belowground microbial community provides nutrients for plant uptake, linking the two systems. My aim was to characterize and describe differences in plant community composition, plant litter quality and microbial community composition between two boreal peatlands in northern Ontario. These peatlands have contrasting plant and microbial communities, the Sphagnum moss-dominated peatland harboring a higher fungi to bacteria ratio compared to the Carex sedge-dominated peatland. Clear open top chambers were installed at both sites to simulate warming. Higher temperatures decreased Sphagnum moss in the Sphagnum-dominated …


The Cost Of Protection: Frost Avoidance And Competition In Herbaceous Plants, Frederick Curtis Lubbe Aug 2019

The Cost Of Protection: Frost Avoidance And Competition In Herbaceous Plants, Frederick Curtis Lubbe

Electronic Thesis and Dissertation Repository

Perennial herbaceous plants in regions that experience winter freezing must survive using belowground structures that can tolerate or avoid frost stress. Soil and plant litter can insulate plant structures from frost exposure, but plants must invest into growth to penetrate through these layers to reach the surface in the spring. The overall goal of my thesis was to test the hypothesis that the protection of overwintering clonal structures by soil or plant litter (frost avoidance) comes at the expense of subsequent reduced growth and competitive ability in absence of freezing stress. I first explored this trade-off with a suite of …


Comparison Of Cyanobacteria Phenotypes With Distinctive Photosynthetic Pigment Compositions To Simulated Lake Browning, Camille Chemali Aug 2019

Comparison Of Cyanobacteria Phenotypes With Distinctive Photosynthetic Pigment Compositions To Simulated Lake Browning, Camille Chemali

Electronic Thesis and Dissertation Repository

Browning of inland waters has been noted over large parts of the Northern hemisphere and is a phenomenon with both ecological and societal consequences. The increase in water color is generally ascribed to increasing concentrations of dissolved organic matter (cDOM) of terrestrial origin. Changes in water color will have profound effects on the phytoplankton composition in freshwater systems. Here, I examined the effect of changes in water color associated with coloured DOM (cDOM) on red and green phenotypes of the cyanobacterium, Pseudanabaena, which emerged to surface blooms in Dickson Lake (Algonquin Provincial Park, Ontario) in the summer of 2014. …


Major Histocompatibility Complex Does Not Affect Mating Patterns In Bluegill Sunfish (Lepomis Macrochirus), Lucas Silveira Jul 2019

Major Histocompatibility Complex Does Not Affect Mating Patterns In Bluegill Sunfish (Lepomis Macrochirus), Lucas Silveira

Electronic Thesis and Dissertation Repository

In many species, individuals prefer mates that are genetically dissimilar at the major histocompatibility complex (MHC). This is likely because it improves offspring resistance to pathogens. Here I provide the first genotypic characterization of the MHC class II peptide binding region in bluegill (Lepomis macrochirus), a species of sunfish, and examine its effect on mating patterns. I hypothesized females would choose to mate with MHC dissimilar males leading to an increase in the resulting offspring’s fitness. I captured females and males during spawning and sequenced the DNA of these fish at the MHC class II putative peptide binding …


The Fruitless Gene Influences Female Mate Preference In Drosophila, Tabashir A. Chowdhury Jul 2019

The Fruitless Gene Influences Female Mate Preference In Drosophila, Tabashir A. Chowdhury

Electronic Thesis and Dissertation Repository

Species can arise as a result of reproductive barriers that prevent gene flow between diverging populations that force them to remain isolated from one another. Behavioural isolation is one of the earliest acting reproductive barriers determined by the evolution of mating preferences that prevent inter-specific matings. Several traits have been identified that contribute to behavioural isolation, but the genetic basis of interspecific female preference is yet to be determined. I used genetic mapping techniques to identify and confirm that the fruitless gene is affecting species-specific female rejection of interspecies males, contributing to the behavioural isolation between Drosophila melanogaster and D. …


Analyzing Avian Incubation With A Computer Algorithm, Tanya T. Shoot Jul 2019

Analyzing Avian Incubation With A Computer Algorithm, Tanya T. Shoot

Electronic Thesis and Dissertation Repository

A stable nest environment is necessary for incubation and development of offspring. Birds vary behaviour to regulate temperature for successful hatchlings. I used a hidden Markov model (HMM) to test how environmental conditions affect incubation behaviour. I examined nest temperatures and behaviours collected from Zebra finches that incubated at 30 °C or 14 °C, then incubated in the same or opposite condition for a second clutch. Data loggers and cameras recorded nest temperature and number of parents on nest. The HMM inferred behaviour from recorded behaviours and temperatures. Temperature and offspring success affected incubation duration. Birds that had successful offspring …


Carbon Cycling In Northern Fen Peatlands – Implications For Climate-Driven Changes Of Ecosystem Carbon Fluxes, Jing Tian Apr 2019

Carbon Cycling In Northern Fen Peatlands – Implications For Climate-Driven Changes Of Ecosystem Carbon Fluxes, Jing Tian

Electronic Thesis and Dissertation Repository

Northern peatlands are important long-term carbon (C) sinks with one-third of northern hemisphere soil organic carbon being stored there. Cool and wet environments at higher latitudes promote C accumulation in northern peatlands by limiting the C loss from decomposition. Northern latitudes are anticipated to experience disproportionately faster climate warming in the future, putting the vast C stores in northern peatlands at risk. There is a concern that northern peatlands are becoming net C sources and further accelerate climate warming. Using both laboratory and field experiments, this doctoral research aimed to explore the potential response of C cycling in northern peatlands …


Contrasting Non-Breeding Ecology Of Swainson’S Thrush (Catharus Ustulatus) In Andean Forest And Shade-Grown Coffee Plantations, Sean Mcelaney Feb 2019

Contrasting Non-Breeding Ecology Of Swainson’S Thrush (Catharus Ustulatus) In Andean Forest And Shade-Grown Coffee Plantations, Sean Mcelaney

Electronic Thesis and Dissertation Repository

Shade-grown coffee plantations provide Neotropical migratory birds an alternative to primary growth forest which is disappearing throughout their non-breeding range. However, it remains unclear whether plantations can provide enough structure to maintain viable non-breeding populations of many species. I studied Swainson’s Thrush (Catharus ustulatus) in the Colombian Andes in a mixture of montane forest and shade-grown coffee plantation. In comparing the two habitats I looked at factors indicative of habitat quality, such as age/sex hierarchies, area of concentrated use, density, diet, and migration timing. My research aimed to determine whether Neotropical migrants benefit from this agroecosystem, and to …